An Amerex model number is not arbitrary. B402, B402T and B402C are the same extinguisher with three different things done to it, and if you order the wrong one you get a unit that either won't mount where you need it or costs nearly three times what you meant to spend.
Amerex publishes no comprehensive legend for this. Two suffixes are spelled out in their parts book; the rest are visible only if you read across enough of their own tables. That's what follows. Where Amerex states a meaning outright it's marked documented. Where it's a consistent pattern across their tables but never defined, it's marked pattern — reliable in practice, but confirm against the part number before ordering.
The anatomy
B 402 TS
A leading letter, a model number, and zero or more suffix letters describing what's different about that version.
The two Amerex actually defines
NM — non-magnetic / M — military (documented)
The parts book prints an actual legend, in the CO2 section:
322NM - 5 lb.
NM - Non Magnetic
M - Military
Non-magnetic units are built without ferrous components for MRI suites, magnetometer bays and similar environments. They also need the matching non-magnetic bracket — Amerex assigns 17737 to the 322NM and the stainless 14315-P to the 270, 272, B270 and B272.
What actually differs is narrower than you'd assume. Comparing Amerex's own parts list for the 322 against the 322NM, the differentiated items are the ring pin (00160-P versus the stainless non-magnetic 06901-P), the bracket, and the cylinder finish. Safety disc, lever, handle, elbow, discharge tube, horn, valve stem, spring, retainer and O-rings are shared.
S — two straps (documented)
On bracket part numbers, S means a second retaining strap. The parts book is explicit: "845S Vehicle Bracket (Red) 2 Strap", "817S Vehicle/Marine Bracket (Red) - 2 Strap", "818S Vehicle/Marine Bracket (Red) - 2 Strap", "821S Vehicle/Marine Bracket (Red) 2 strap".
Anything that moves — a truck, a boat, a forklift — is worth the second strap.
B — black (documented)
The parts book pairs red and black finishes throughout: 845 and 845B, 817 and 817B, 818 and 818B, 817S and 817SB. Purely cosmetic, and it stacks with S.
The rest, derived from Amerex's tables
CG — Coast Guard (documented)
US Coast Guard approved configuration. Amerex states of the wet chemical units: "MODELS C260CG & C262CG COAST GUARD APPROVED *MUST USE 810CG BRACKET (sold separately)", and glosses the bracket directly as "810CG (USCG)".
This one has teeth. The 810CG is a distinct part number from the standard 810, and the approval covers the unit and its listed bracket together.
T — ships with a vehicle bracket (pattern)
Amerex never states this in words, but their specification tables make it unambiguous. The INCLUDED BRACKET row reads "WALL/VEHICLE" across the paired models, and the catalog prints them as B500(T) and B402(T) with separate part numbers — 15312 and 15310, 15280 and 15281. The B417T, which exists only as a T model, has "Vehicle" alone.
A B402T is a B402 that arrives ready to mount in a truck. If you're mounting in a vehicle, order the T variant rather than the base unit plus a bracket. The premium is $5 on the B500 and $9 on the B402 — well under the price of a separate vehicle bracket — and you don't end up with a spare wall hanger.
TS — ships with a two-strap vehicle bracket (pattern)
T plus S, behaving exactly as that reads. Our B500TS is the two-strap version of the B500T.
C — chrome cylinder (pattern)
Amerex's spec tables carry an "OPTIONAL CHROME CYLINDER: Yes" row against the models that offer it, and the chrome versions appear as separate part numbers with a C. Chrome is cosmetic — hotel lobbies, showrooms, architectural installations — and it is not cheap. Our B402 is $80.00; the B402C is $220.00 for identical firefighting capability.
T and C stack, and the clearest worked example is the 376T/376TC and B410T/B410TC Purple K vehicle family — the same two Purple K units offered in red or chrome, each shipping with the vehicle bracket.
G — galvanized (pattern)
On bracket part numbers. Amerex doesn't define the letter, but describes the heavy-duty range as "Hot dip galvanized USCG brackets" and pairs 809/809G, 810/810G and 811/811G in the USCG bracket column. For salt, chemical or permanent outdoor exposure, the 809G is the step up from the 809.
Don't confuse this with Z on a bracket. Amerex also offers the 809, 810 and 811 with "an optional zinc primer undercoat (809Z / 810Z / 811Z)" — a different treatment from galvanizing, and unrelated to the Z-Series extinguisher line below.
R — rubber treads (documented, wheeled units)
On wheeled extinguishers, Amerex labels the spec row "'R' MODEL WITH NON-SPARKING RUBBER TREADS" — the only place a suffix letter is tied to its meaning in the wheeled catalog.
The base wheel varies by size, so R is adding treads to different things: the 125 lb units run 16×4 semi-pneumatic tires, while the 300 lb units run 36×6 steel wheels. Amerex describes the 680R and 681R as running on "36" non-sparking rubber tread steel wheels." Non-sparking matters where you're rolling a 250 lb unit across a fuel apron — it's why the 493R at $10,511 costs more than the 493 at $9,413.
Z-Series and HT Series (documented)
Product lines, not modifiers. Z-Series is Amerex's High Performance galvanized line. HT Series is described by Amerex as "THE HIGH PERFORMING HT-SERIES for commercial settings, once exclusive to the aerospace" industry — Halotron BrX agent, aluminum or steel cylinders, and importantly non-rechargeable with a 12-year service life. Our 551 is the largest of the four HT models, and the one Amerex notes uses a steel cylinder rather than aluminum.
The axis that actually governs parts: valve material
More consequential than any suffix. Amerex builds the same capacities with two different valve assemblies, and every dry chemical table splits on "VALVE TYPE: ANODIZED ALUMINUM" versus "CHROME PLATED BRASS."
This is not a trim level — it changes which service parts fit, and the model name does not tell you which you have. In Amerex's own 10 lb ABC line, the B456 is aluminum valve and the B441 is brass valve. Same capacity, same 4A:80B:C rating, different internals.
The recharge adapters make the split concrete: the 01720 serves aluminum valve dry chemical units, the 02141 serves brass valve, high performance and Class D. With one documented exception: Amerex lists the 02141 for 20 lb aluminum valve units too. Ordering by capacity alone will get you the wrong one; so will ordering by valve type alone at 20 lb.
The buried one: brackets changed in 2004
This is the trap almost nobody knows about, and it is stated plainly in Amerex's parts book — on a page most people never open.
For nine models, the correct wall bracket depends on when the extinguisher was built.
| Models | Built before 2004 | Built 2004 or later |
|---|---|---|
| 361, 372, 408, 415, 423, A411, A412, A413 | 01007-P | 00577-P |
| 419 | 01007-P | 00575-P |
Amerex asterisks those models on each list and footnotes them: "(* For extinguishers manufactured before 2004)" on the 01007-P list, "(* For extinguishers manufactured 2004 or later)" on the other two.
A technician servicing a 2001-build A411 who looks up "A411 wall bracket" anywhere on the internet will be sent to the wrong part. Check the date of manufacture on the nameplate before ordering a bracket for any of those nine models.
Two related models sit in a documentation gap worth knowing about: the 692 and 693 are asterisked on the 00577-P list for units built 2004 or later, but Amerex does not state which bracket the earlier builds took. If you have a pre-2004 692 or 693, ask rather than assume.
What not to guess
The leading letter doesn't tell you the valve. The B prefix carries no information — the B456 is aluminum valve and the B441 is brass. Nor does its absence: the 423 is brass but the 377 is aluminum. Treat the leading letter as part of the name and read the valve type off the spec table or the unit itself.
The -P suffix on part numbers (01007-P, 04834-P, 06901-P) runs throughout the parts book on service components. Where a further numeric suffix follows, that trailing figure is the pack quantity (pattern): 06866-P001 is a single 817SB bracket, 06866-P006 is a pack of six.
AFT appears on certain Halotron BrX part numbers. We have not found it defined in any Amerex document, and pricing on those SKUs differs sharply from the standard-channel equivalents — ask before assuming what you're ordering.
Identifying what you actually have
- Read the nameplate, not the paint. Model number, part number and date of manufacture are all printed there.
- Note the valve material — anodized aluminum or chrome-plated brass. This governs internal parts.
- Note the date of manufacture if it's one of the nine models above.
- Measure the cylinder diameter if you're ordering a bracket. Brackets fit by diameter, not model — see which Amerex bracket fits your extinguisher.
Every product here is searchable by its Amerex part number. Type the number off the nameplate into the search box and you'll land on the exact item.
Not sure what you're looking at? Send us the model and the date from the nameplate and we'll identify it — request a quote
Sources
Meanings marked documented are quoted from Amerex Corporation's published Portable & Wheeled Parts Book (P/N 27277) and their hand-portable and wheeled extinguisher catalogs. Meanings marked pattern are derived from consistent usage across those same documents where Amerex does not state the rule. The 2004 bracket footnotes are quoted verbatim from the parts book.
Amerex publishes no comprehensive model-number legend, and product lines change. Where a part number matters, confirm it against the extinguisher's nameplate and Amerex's current parts book before ordering.
ShopAmerex.com is owned and operated by Centurion Holdings Group LLC, an independent authorized distributor of Amerex Corporation products. We sell equipment and factory OEM service parts — we do not perform inspection, service, hydrostatic testing or recharging.